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Lithium-sulfur batteries are theoretically ideal for powering gadgets. They have more than twice the energy density of lithium-ion packs, but at a much lower cost thanks to sulfur's dirt-cheap price. There's just one problem: sulfur dissolves, giving the battery a short lifespan. That's where Berkeley Lab might help. It recently discovered that a derivative of red seaweed, carrageenan, can stabilize a lithium-sulfur battery and make it practical for more devices. If you use the seaweed derivative as a binder (the "glue" that keeps a battery's active materials together), it reacts with the sulfur and prevents it from dissolving. The ultimate goal is to produce cells that last for "thousands" of charging cycles, or better than many batteries you see today.
Some of the practical benefits are immediately evident. Your phone could last much longer on a charge even as the price went down. However, the researchers are eager to point out the potential uses in transportation. As lithium-sulfur is lighter than lithium-ion, it's ideal for drones and other electric aircraft. The technology could also prove to be a minor miracle for electric cars. GM is one of Berkeley Lab's partners, so it's easy to imagine the Chevy Bolt maker using lithium-sulfur in future EVs that are both more affordable and drive much further on a charge.
The gotcha? It's still quite early. The team needs to understand more about how the derivative interacts with sulfur, and whether or not it's reversible if necessary. It may be a long while before you see a lithium-sulfur battery on the road or in your pocket. All the same, it's notable that the technology is even on the roadmap. We've seen many promises of longer-lasting batteries, but the low-cost nature of this solution should give it a better shot at reaching real-world products.